Sapphires have been treated for centuries to improve their colour, clarity and lustre. However, the disclosure of these treatments has not always been common practice among traditional jewellers.
The way a sapphire is enhanced can directly affect its overall value. Therefore, it’s very important to know how sapphires are routinely treated in the industry.
The most common type of treatments among sapphire are:
An acceptable and oldest trade practice, heat treatment replicates a natural process of heating beneath the earth’s crust and permanently improves the colour, lustre and clarity of the sapphire.
Are heated sapphires valuable?
Absolutely, fine sapphires with excellent colour, lustre and clarity being rare, even though they are heated, they can cost in 10s of thousands of dollars depending on their exact colour.
For example, a heated 2.00 carat round blue sapphire can range between US$2,550.00 ~ US$3,750.00 whereas an unheated 2.00 carat round blue sapphire can be anywhere between US$3,150.00 ~ US$4,650.00
What percentage of sapphires are heat treated?
It is estimated that over 98% of the sapphires available in the market are heated to some degree.
Is heat treatment permanent?
Yes, the heat treatment is permanent and does not affect the overall integrity, structure and durability of the sapphire.
Lattice diffusion/ Beryllium treatment
Also known as Thermal treatment, Lattice diffusion is a form of heat treatment where foreign substance (chemicals) are used to artificially change the colour of sapphire. In this process, the sapphire is heated to extreme temperatures nearly to melting point and then infused with chemicals (such as beryllium or titanium) to alter its colour.
Its effects are superficial, and in most instances the sapphire's colour is not permanent.
To improve the appearance, sapphires are often filled with a glass to help camouflage the breaks, cracks and inclusions. These artificially enhanced gems are not at all valuable and the treatment is not permanent.
From our sourcing team
The nature of treatment can influence the overall value of the sapphire to a great extent hence in case the sapphire treatment is not disclosed, it is worth asking about the treatment before selecting the sapphire.
At Nolan and Vada, we do not sell or recommend chemically treated (Lattice Diffused) or fracture filled sapphires. All our sapphires are either unheated or heated and carefully hand-picked from over 1000s of sapphires for their overall brilliance, colour and clarity.
As a part of our custom process, our consultant will disclose any treatments, share images/ videos of sapphire for your selection and approval.